Accurate copper loss analysis of a multi-winding high-frequency transformer for a magnetically-coupled residential micro-grid

Abstract

Improvements in characteristics of magnetic materials and switching devices have provided the feasibility of replacing the electrical buses with high frequency magnetic links in micro-grids. This effectively reduces the number of voltage conversion stages, and the size and cost of the renewable energy system. It also isolates the converter ports which increases the system safety and facilitates bidirectional power flow and energy management. To design the magnetic link optimally, an accurate evaluation of copper loss of the windings considering both current waveforms and parasitic effects is required. This paper studies the accurate copper loss analysis of a three-winding high-frequency magnetic link for residential micro-grid applications. Due to the non-sinusoidal nature of the voltage and currents, the loss analysis is carried out on a harmonic basis taking into account variations of phase shift, duty ratio and amplitude of wave-forms. The high frequency skin and proximity effects are taken into account. The maximum and minimum copper loss operating points of the converter and their dependency on the phase shift and duty ratio of the waveforms are studied and simulation results are presented.

Comparative analysis of DC to AC conversion cells for application in PV‐linked grid‐connected modular multi‐level cascaded converters

“…The most common MAB converter topologies are triple‐active bridge (TAB) [12], and quadruple‐active bridge (QAB) [13]. However, increasing the number of bridges and transformer windings to more than four leads to the complexity in the structure and design of MWT [14, 15]. Application of MAB converter with different configurations in the modular smart transformers and the resulting advantages are studied in [10] and only the FB topology is considered as dc–ac conversion cell in the proposed systems.…”

A Topology of DC-DC Converter Based on Multi-Winding Transformer for Grid Integration of Multiple Renewable Energy Resources

“…This provides an isolation between the ports, and facilitates the connecting of several sources with substantially different operating voltages, thanks to the transformer turns ratio [16]. On the other hand, a simpler power flow control can be achieved by using a phase shift control technique [17][18][19]. A complete study on the magnetically coupled multi-port converters has been presented in [16][17][18][19][20].…”

“…On the other hand, a simpler power flow control can be achieved by using a phase shift control technique [17][18][19]. A complete study on the magnetically coupled multi-port converters has been presented in [16][17][18][19][20]. It should be noted that the system operation and design of the multi-winding high-frequency transformer become very complex in the case of a large number of windings [21][22][23][24].…”

“…Inventions 2020, 5, 31 2 of 17 The power flow in the proposed converter has been drawn from two different DC sources, and delivered to the load individually and simultaneously [16]. The converter is able to accommodate the voltage variations of the sources by using the current-fed H-bridge converters.…”

Copper Loss Analysis of a Multiwinding High-Frequency Transformer for a Magnetically-Coupled Residential Microgrid

“…In this paper, a general method of copper loss calculation in the multi-winding magnetic links supplied by the variable phase shift, amplitude, and the duty ratio square-wave voltages is proposed [30]. The method can be applied to the multi-winding magnetic links with the square-window magnetic cores for energy integration in micro-grids or SST applications.…”